When drilling a wellbore, knowledge of surrounding features and other wellbores may be necessary to avoid intersecting the wells. In one example, when sidetracking a wellbore where another wellbore is located in close proximity, knowledge of the location of the second well relative to the first well may be necessary to avoid drilling into the second well. In another example, where one wellbore of two splitter wells—wellbores spudded from inside the same surface conductor—is to be sidetracked, because the two splitter wells are in close proximity, the risk of colliding with the second splitter well may be increased due to the close proximity of the wells. Typically, magnetic ranging may be used to determine range and distance between wells when the well to be sidetracked, referred to herein as the drilling well, is uncased and the second well, referred to herein as the target well, is cased. However, where the drilling well is cased, magnetic fields from the target well may be shielded or perturbed by the casing.